Can't test a configuration that depends on Rename-NetAdapter

[nmdange2]

Details of the scenario you tried and the problem that is occurring

I am attempting to run Test-DscConfiguration when I have to rename a network adapter and then assign a vlan. Even though I have DependsOn set, Test-DscConfiguration on the netadapteradvancedproperty is throwing a fatal error because the name does not exist. I am not sure if this is really an issue with this module or how Test-DscConfiguration works. I can successfully apply the configuration, but I can't test the configuration to see what changes will be made before applying them.

Verbose logs showing the problem

VERBOSE: : LCM: [ Start Resource ] [[NetAdapterName]RenameSMBNIC1]
VERBOSE: : LCM: [ Start Test ] [[NetAdapterName]RenameSMBNIC1]
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Test-TargetResource: Testing the
network adapter Name 'SMB_A'.
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Find-NetworkAdapter: Finding
network adapters matching the parameters.
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Test-TargetResource: Finding
network adapter matching search criteria.
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Find-NetworkAdapter: Finding
network adapters matching the parameters.
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Find-NetworkAdapter: 1 network
adapters were found matching the parameters.
VERBOSE: : [[NetAdapterName]RenameSMBNIC1] Test-TargetResource: network
adapter Name 'Ethernet 2' does not match the adapter 'SMB_A' that was found. Rename required.
VERBOSE: : LCM: [ End Test ] [[NetAdapterName]RenameSMBNIC1] False in 0.1410 seconds.
VERBOSE: : LCM: [ End Resource ] [[NetAdapterName]RenameSMBNIC1]
VERBOSE: : LCM: [ Start Resource ] [[NetAdapterAdvancedProperty]VlanSMBNic1]
VERBOSE: : LCM: [ Start Test ] [[NetAdapterAdvancedProperty]VlanSMBNic1]
VERBOSE: : [[NetAdapterAdvancedProperty]VlanSMBNic1] Test-TargetResource:
Checking if network adapter exists or not.
VERBOSE: : LCM: [ End Test ] [[NetAdapterAdvancedProperty]VlanSMBNic1] False in 0.1250 seconds.
VERBOSE: : LCM: [ FAILEDCompare ] Completed processing compare operation. The operation returned
False.

Suggested solution to the issue

Does not throwing a fatal error in Test-TargetResource when the adapter doesn't exist make sense to do?

The DSC configuration that is used to reproduce the issue (as detailed as possible)

NetAdapterName RenameSMBNIC1
{
	NewName = "SMB_A"
	MacAddress = $Node.SMB_NIC_1_MacAddr
	PhysicalMediaType = '802.3'
}

NetAdapterAdvancedProperty VlanSMBNic1
{
	NetworkAdapterName = "SMB_A"
	RegistryKeyword = "VlanID" 
	RegistryValue = 101
	DependsOn = "[NetAdapterName]RenameSMBNIC1"
}

The operating system the target node is running

OsName : Microsoft Windows Server 2019 Datacenter
OsOperatingSystemSKU : DatacenterServerEdition
OsArchitecture : 64-bit
WindowsVersion : 1809
WindowsBuildLabEx : 17763.1.amd64fre.rs5_release.180914-1434
OsLanguage : en-US
OsMuiLanguages : {en-US}

Version and build of PowerShell the target node is running

PSVersion 5.1.17763.592
PSEdition Desktop
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.17763.592
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1

Version of the DSC module that was used ('dev' if using current dev branch)

7.3.0.0

[PlagueHO]

Hi @nmdange2, thank you for raising this. You do raise a good discussion point: should NetAdapterAdvancedProperty (and other similar networking resources) throw an exception in Test-TargetResource if the adapter does not exist?

At the moment, that is the behavior we have adopted, but it might be worth reconsidering.

Instead, should Test-TargetResource display a warning and just return $true instead if the adapter does not exist?

For Set-TargetResource however, we'd definitely want to throw a fatal exception.

Off the top of my head, I can't think of specific scenarios where removing the fatal error would cause a major issue. @johlju - any thoughts on this one?

[nmdange2]

I would probably suggest Test-TargetResource should return $false if the adapter does not exist.

[johlju]

Sorry for taking so long to answer. @nmdange2's comment made the notification jump to the top of the list. 😃

I don't think neither Get-TargetResource or Test-TargetResource should throw an error if the adapter does not exist. Both Get-DscConfiguration and Test-DscConfiguration should be able to be run without throwing an error. Or using Invoke-DscResource with the method Test or Get.

When running Set-TargetResource either through Start-DscConfiguration or Invoke-DscResource with the method Set then the resource should throw an error if the adapter does not exist.

Test-TargetResource should return $false if Get-TargetResource returns that the adapter is not in desired state - not having the expected adapter is not the desired state. Get-TargetResource could have a red-only property AdapterPresent to further evaluate the state of the resource. This new property can be used by both the function Test-TargetResource or a user when running Get-DscConfiguration.